By Sarah Marsh

HAVANA, May 10 (Reuters) - Cuba's new Mariel deepwater container terminal hopes to further its plan to become a regional shipping hub by completing dredging next year so it can receive mega-sized vessels, its general manager Charles Baker said on Thursday.

The terminal in Mariel Bay, 45 kilometers (28 miles) west of Havana, is located in an industrial park where Cuba is seeking to attract foreign investors with tax and customs breaks, as part of its market reform plan to boost the anemic economy.

After opening in 2014, the terminal started receiving the container shipping that previously went through Havana, which has become focused on receiving increasing numbers of cruise ships.

Last year, the Mariel terminal processed a record 335,000 20-foot (6-meter) equivalent cargo units, 2 percent more than in the previous year, Baker said, adding he expected light growth again this year.

But, given most business has come so far from Cuban imports and exports, it has been limited by the performance of the local economy, which has struggled with a cash crunch in recent years.

In the long run, Mariel's backers want it to exploit expansion of the Panama canal by providing good quality facilities, and become a hub for ocean carriers which would then feed the eastern coasts of the Americas with smaller vessels.

For that, it needs to dredge its canal deeper, so it can receive the new breed of huge container vessels known as post-Panamax ships. The U.S. embargo is also an ongoing obstacle for trade with Cuba's northern neighbor.

"The dredging project should complete its next phase by the end of this semester, which will enable us to receive post-Panamax ships that are 335 meters in length," Baker told a news conference at the port.

He added that dredging would continue and finish next year, allowing ships that are 366 meters long to use the terminal.

It would have been practically impossible to make the Havana port suitable for receiving such large ships because of a traffic tunnel under the channel.

The Mariel terminal, with its four hulking post-Panamax cranes visible from afar, has the capacity to handle around 800,000 cargo containers annually, compared to Havana's 350,000.

Cuba hopes to develop the Mariel industrial park in order to ship more Cuban exports from the terminal, too. (Reporting by Sarah Marsh, Editing by Rosalba O'Brien)